Fall 01: Exam 1. Ch 1-4 100points Name If you do not want your ...
Fall 01: Exam 1. Ch 1-4 Name
100points
If you do not want your graded exam placed in the box outside my office, then please tick here Answer all the questions. 1) Draw Lewis structures (lines for bonds and dots for all lone pairs) for the following molecules: (8pts) (a)
BCl3
O O
(b)
H2N (c)
OCH3 (d)
2) Draw a Lewis structure for this molecule. (3pts) O
NHCH3
O
3) Also indicate the hybridization of each C, N, and O atom in the above molecule. (10pts)
Fall01-org1ex1
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3(b) There is a bonus point if you can name this drug which creates states of entactogenesis and empathogenesis in users. Side effects have been shown to include lowered brain serotonin levels, which results in long term depression and memory degradation.
4) (i) Write all the resonance forms for the following two species. (ii) Indicate which are major and minor contributors (or if they are the same energy). (iii) Use curly arrows to show the movement of electrons which converts one into the others. (10pts) _ O
(a) O
(b)
N
+
5) (i) Give any two definitions of an ‘acid’, and state the name/inventor of each definition. (4pts)
(ii) Indicate which reactant is acting as a NUCLEOPHILE and which is acting as an ACID for the following reactions. (4pts) (iii) Also circle the conjugate acid of the basic species. (2pts) (a) HNO3 + H2O → H3O+ + NO3(b) CH3S- + CH3OCH2-Br → CH3SCH2OCH3 + BrFall01-org1ex1
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6) Explain the difference between structural isomers and stereoisomers? (3pts)
7) Draw and label an energy level diagram showing an endothermic reaction which proceeds via a single intermediate, and the second step of this two step process is rate determining. (10pts)
8) Using Newman projections, draw any two different conformations of cyclohexane, and indicate which of the two you have drawn would have the higher energy. (8pts)
Fall01-org1ex1
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9) Name the following compounds in IUPAC form. (15pts) (a)
(b)
H3C (c)
CH3 H
CH3 H
H
CH2CH3 H
H
CH3 CH3
(d)
(e)
CH2CH2CH3
F F
Fall01-org1ex1
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10) The chlorination of methane (CH4) with chlorine gas (Cl2) results in Chloromethane (CH3Cl). This reaction is said to proceed via a “free radical chain mechanism”. (i) Explain what a free radical is (3pts)
(ii) What is meant by a chain process? (2pts)
(iii) Explain what a termination step is (2pts)
(iv)
Using “fish hook” arrows (which represent movement of ONE electron), draw the mechanism for the two propagation steps that the result in the formation of chloromethane. (6pts) Cl•
H3C•
H—CH3
→
Cl—Cl
H—Cl
→
Fall01-org1ex1
CH3—Cl
•CH3
Cl•
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11) Explain why the methyl radical ( •CH3 ) has H-C-H bond angles of 120°. (10pts)
Fall01-org1ex1
page6
100points
If you do not want your graded exam placed in the box outside my office, then please tick here Answer all the questions. 1) Draw Lewis structures (lines for bonds and dots for all lone pairs) for the following molecules: (8pts) (a)
BCl3
O O
(b)
H2N (c)
OCH3 (d)
2) Draw a Lewis structure for this molecule. (3pts) O
NHCH3
O
3) Also indicate the hybridization of each C, N, and O atom in the above molecule. (10pts)
Fall01-org1ex1
page1
3(b) There is a bonus point if you can name this drug which creates states of entactogenesis and empathogenesis in users. Side effects have been shown to include lowered brain serotonin levels, which results in long term depression and memory degradation.
4) (i) Write all the resonance forms for the following two species. (ii) Indicate which are major and minor contributors (or if they are the same energy). (iii) Use curly arrows to show the movement of electrons which converts one into the others. (10pts) _ O
(a) O
(b)
N
+
5) (i) Give any two definitions of an ‘acid’, and state the name/inventor of each definition. (4pts)
(ii) Indicate which reactant is acting as a NUCLEOPHILE and which is acting as an ACID for the following reactions. (4pts) (iii) Also circle the conjugate acid of the basic species. (2pts) (a) HNO3 + H2O → H3O+ + NO3(b) CH3S- + CH3OCH2-Br → CH3SCH2OCH3 + BrFall01-org1ex1
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6) Explain the difference between structural isomers and stereoisomers? (3pts)
7) Draw and label an energy level diagram showing an endothermic reaction which proceeds via a single intermediate, and the second step of this two step process is rate determining. (10pts)
8) Using Newman projections, draw any two different conformations of cyclohexane, and indicate which of the two you have drawn would have the higher energy. (8pts)
Fall01-org1ex1
page3
9) Name the following compounds in IUPAC form. (15pts) (a)
(b)
H3C (c)
CH3 H
CH3 H
H
CH2CH3 H
H
CH3 CH3
(d)
(e)
CH2CH2CH3
F F
Fall01-org1ex1
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10) The chlorination of methane (CH4) with chlorine gas (Cl2) results in Chloromethane (CH3Cl). This reaction is said to proceed via a “free radical chain mechanism”. (i) Explain what a free radical is (3pts)
(ii) What is meant by a chain process? (2pts)
(iii) Explain what a termination step is (2pts)
(iv)
Using “fish hook” arrows (which represent movement of ONE electron), draw the mechanism for the two propagation steps that the result in the formation of chloromethane. (6pts) Cl•
H3C•
H—CH3
→
Cl—Cl
H—Cl
→
Fall01-org1ex1
CH3—Cl
•CH3
Cl•
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11) Explain why the methyl radical ( •CH3 ) has H-C-H bond angles of 120°. (10pts)
Fall01-org1ex1
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